Race: Understanding Human Diversity - Part 3 (Finale)
Representations of the Out-of-Africa Expansion for Homo sapiens; A shows a map of early Eurasian individuals, B breaks down these movements temporally, showing known gene flow with other human species (from Bergström, et al. 2021)
In the previous post, I discussed a number of examples of human physical and genetic traits and how they came to be. Features like skin color, hair texture, skull shape, etc were all either the products of adaptation to environment or genetic drift. In prehistory, human numbers were small and it was easier for mutations to take hold and spread across demes and populations. That said, many of these traits are underpinned by multiple genes, and there is no evidence that they all necessarily correlate with each other nor that they can serve as specific markers for human races.
The most accurate way to understand how our current human diversity came to be is through genomics, and the best way to see that is by tracking the migrations and expansions of people as far back as we can. In the traditional understanding of human diversity, biological anthropologists argued that races originated from ancestral stocks that spread across the earth and, while they were not necessarily immune to interbreeding, nonetheless remained distinct until the last 500 years or so when colonialism "connected the world together".
The last few decades of modern genetics has shattered this view. Humanity has been mobile and promiscuous from the very beginning, with the boundaries between groups often considered "races" to have been broken time and time again. We now understand that unique physical traits not only are spread by migration, but that migrating groups change as well following settlement onto new lands.
As a recent review paper explains: "Generally, the evidence suggests that selective pressures and adaptations occur at the individual, family, and community levels. Consequently, across levels there are negotiations, interactions, and feedbacks that shape migration outcomes and the trajectory of evolutionary change" (Bell, 2023).
So let's track the journey of humanity and show what modern research has to say about where we all came from...
Species Origins
A computer model showing evidence of deep connections and separations predating the origin of Homo sapiens (from Cousins, et al. 2025)
Our species, Homo sapiens, shares a recent common ancestor with two extinct species, the Neanderthals (Homo neanderthalensis) and the Denisovans (currently unclassified, perhaps Homo longi?). Morphological and genetic studies are not in ready agreement as to when these species diverged from each other; it could be as recent as ~550 thousand years ago or over a million years ago (Liu, et al. 2021; Feng, et al. 2025). It is also unclear as to where this divergence occurred. It may very well have been in Africa, but alternative locations have been suggested for Southwest Eurasia (Reich, 2018).
The Middle Pleistocene fossil record in these regions nonetheless records a great diversity in human remains. Individuals from sites like Jebel Irhoud, Omo, Florisbad, Herto, and Skhul show a mosaic of features between earlier hominins and modern Homo sapiens (Mounier & Lahr, 2019). This has suggested to many paleoanthropologists in the last few years that we may need to model the origin of Homo sapiens as "multiregional", like a braided-stream of ancestry where populations diverged, merged, and diverged again, with some of these events eventually giving rise to the last common ancestor of modern humans as we would recognize them (Bergström, et al. 2021). That is to say, humans with a globular cranium, a bony chin, and a narrow, less-flared pelvis. Computer modeling utilizing sequenced genomes has indicated a possibility that our direct ancestors may have intermingled at least twice (Cousins, et al. 2025) and constituted "weakly structured" stem-groups which did not exist as "well-defined and stable populations over hundreds of thousands of years" (Ragsdale, et al. 2023). These groups also seem to include the ancestors of the Neanderthals and Denisovans, further demonstrating how closely-related we are to these relatives of ours.
Homo sapiens in Africa
Two charts showing the degree of relatedness and admixture between Indigenous African peoples (from Fan, et al. 2023)
Once our species emerged between 300 and 200 thousand years ago, fossil and genetic evidence shows that we had a widespread distribution across the African continent. Multiple times had populations moved, met, admixed (interbred), and went their separate ways, so that it has become difficult to pinpoint the "roots" of ancestry, as is expected from multiregional evolution.
Nonetheless, there do appear to be some connections that can be made between the ancestors of Indigenous African groups. The Khoesan-speaking peoples of Southern Africa (e.g. the Ju|’hoansi and the !Xoo, whose language includes "click-consonants") appear to share significant amounts of ancestry with Central African rainforest peoples (e.g. the Mbuti and the Aka), with evidence of divergence between 285 and 150 thousand years ago (Fan, et al. 2023). This makes their ancestors part of a "sister-clade", a term from cladistics designating two closely-related groups. That said, these groups did not remain isolated for very long, quite the contrary! For example, Khoesan-speaking groups in East Africa (e.g. the Hadzabe and the Sandawe) appear to share significant amounts of ancestry with Southern African Khoesan, 71% between the Hadzabe and SA Khoesan and 38% between the Sandawe and SA Khoesan; the remaining ancestry in these groups is shared with other East African populations (Fan, et al. 2023). There is also evidence that the ancestors of the South African Khoesan may have originally emerged in East Africa and subsequently expanded their range southward, all the while contributing geneflow to their northern relatives within the last 12 thousand years.
Genetic modelling of African ancestries, with an emphasis on West African groups (from Lipson, et al. 2020)
By 200 thousand years ago at least three more ancestral groups were present across Africa alongside the Khoesan-speaking and Central African groups (Liu, et al. 2021).
The third group is a mysterious genetically-unsampled population that has been detected in the ancestries of both living West Africans and an ancient 4,500 year old individual from Mota, Ethiopia. Archaeologists have yet to have unearthed or extracted ancientDNA from an individual who hailed from this group, nor is there an exact idea of where these people originally lived (Llorente, et al. 2015).
The fourth group represents the ancestral populations of Northern Africa. These peoples seem to have shared ties with both the ancestors of living West and East African peoples, and have bestowed a significant amount of DNA to a 15 thousand-year-old individual who was excavated from the site of Taforalt in Morocco (Loosdrecht, et al. 2018). North Africa has been a bit of a blind-spot in ancientDNA studies, but a growing picture is emerging for a long-standing regional continuity between the earliest Homo sapiens in the region and the late Pleistocene peoples of the Iberomaurusian culture (Bergmann, et al. 2022; Röding, et al. 2022).
The fifth group is of strong relevance as it contributed the majority of the remaining ancestry for living Indigenous African peoples as well as the group that emerged in Eurasia ~80 thousand years ago (Liu, et al. 2021; Lipson, et al. 2020). Nonetheless, it should be clear that Africa was home to a great diversity of early peoples which evolved over time through a fluid, mosaic process in which some groups emerged, admixed, and either stayed around or became subsumed by other groups. It's a fool's errand to try to find races here.
This fifth group appears to have undergone an evolutionary radiation between 80 and 60 thousand years ago, likely in East Africa (Lipson, et al. 2020). One population spread westward and gave rise to the majority of ancestry in living Niger-Congo-speaking peoples, and appears to have effectively subsumed or pushed-out earlier populations related to both the Central African rainforest peoples and the 8-3,000 year old individuals at Shum Laka, Cameroon (Lipson, et al. 2020). From there, these groups underwent several divergences and by 6-4,000 years ago the Bantu-speaking agriculturalists had emerged in present-day Cameroon. This group would go-on to spread and settle across much of Africa south of the Sahara, today making up ~30% of the continent's population (Fortes-Lima, et al. 2023). Another population stayed in East Africa and gave rise to various agro-pastoralist (farming & herding) groups that spoke Nilo-Saharan and Afroasiatic languages: these two populations, in turn, seem to have diverged from each other between 35 and 22 thousand years ago (Fan, et al. 2023). Throughout these movements, older populations responded in various ways, through coexistence, conflict, genetic admixture, or "voting with their feet".
"Out of Africa"
Highly-simplified representation of ancestral groups following the ~80 KYA 'Out of Africa' expansion (from Vallini, et al. 2024)
Related to this fifth group is a population which has subsequently gone on to populate the rest of the planet. Known to ancientDNA researchers as "Non-Africans", they would have remained African peoples or at least have been close-neighbors when they first emerged. This is evidenced by the signature of a currently-unknown population known as Basal Eurasians, who represent the oldest known genetic split from the Non-African lineage (Reich, 2018). It is unclear just where the Basal Eurasians emerged, and when, but their genes have been found in both ancient and present-day Europeans and peoples in the Middle East and North Africa, and this hints that they were a widespread and long-lived group.
Around 80 thousand years ago there is greater evidence of a sustained presence of Homo sapiens in Southwest Asia, suggesting that an Out of Africa (henceforth OoA) population expansion has begun. Genetics picks up a significant movement of peoples between 70 and 60 thousand years ago, but it isn't until about 45 thousand years ago that large waves of people began to spread further into Europe and Asia. Various studies have proposed a "hub" in either the Arabian Peninsula or the Iranian Plateau where the OoA population settled for several thousand years, gaining genetic mutations which provided adaptational benefits for the new, cooler environment (Tobler, et al. 2023; Vallini, et al. 2024).
From there, we find traces of a smaller population expansion in the remains of two individuals, one found at Zlatý kůň, Czechia and another at Ranis, Germany, both dated to over 45 thousand years ago. This group of people does not seem to have contributed ancestry to anyone in Europe today and may represent a short-lived population in the region (Vallini, et al. 2022). Their genetic signature contains evidence of recent interbreeding with Neanderthals, and in fact has been tied to a significant admixture event that occurred between 49 and 45 thousand years ago with the OoA group and a Neanderthal population (Sümer, et al. 2024). This event has been forever sealed in the genomes of most humans today who are not of Indigenous African ancestry: as much as 2–3% of the genome comes from Neanderthals. This is an area of active research, and there is evidence of both positive and negative selection for various genes shared with us from this species of human (Iasi, et al. 2024).
While there is evidence from the archaeological record of other - sometimes substantially older - groups of Homo sapiens in Eurasia and Oceania (e.g. at Fuyan Cave in China ~100 KYA and Madjedbebe in Australia ~65 KYA), these have not yet been tied to any genetic lineages and may represent groups which contributed little if any ancestry to living peoples (Bergström, et al. 2021). As well, earlier research which seemed to find genetic evidence of an older pre-OoA movement of peoples that reached New Guinea has since been called into question (Mondal, et al. 2025).
West Eurasia
Genetic evidence of three separate sweeps into Eurasia between 45 and 38 thousand years ago (from Vallini, et al. 2022)
By 45 thousand years ago, there was a significant split from the OoA population into two groups. One population ventured eastwards towards Southeast Asia, while the other migrated westwards towards Europe. Both groups utilized Initial Upper Palaeolithic technologies, consisting of core, blade, and flaking stone tools constructed from Levallois techniques (Bellwood, 2022). The ancientDNA from several individuals of this group have been uncovered, including from Ust’-Ishim from Russia ~45 thousand years ago, Oase1 from Romania ~40 thousand years ago, Bacho Kiro from Bulgaria ~46-43 thousand years ago, and Tianyuan from China ~40 thousand years ago. They are all quite closely related to each other, even separated by such distances, suggesting that admixture between Western and Eastern Eurasian groups was maintained (Hajdinjak, et al. 2021). However, though the members of the Eastern groups survived on their own for successive generations, members of the Western groups would eventually be subsumed by a second wave of migrants around 38 thousand years ago (Vallini, et al. 2022). This Upper Paleolithic expansion, the first to feature blade tools, characterized what ancientDNA researchers call the European Early Modern Humans throughout western and eastern Europe and the Ancient North Eurasians in Siberia. We'll look at the former first.
The genetic history of glacial and post-glacial Europe (from Posth, et al. 2023)
A recent paper has elucidated the subsequent genetic history of European populations through the Paleolithic or Forager Age (Posth, et al. 2023). In essence, following the Upper Paleolithic expansion ~38 thousand years ago, Europe was populated by two groups of differing ancestries, represented by the western "GoyetQ116-1" population and the eastern "Kostenki" population. By 33 thousand years ago, these groups had begun admixing and gave rise to the "Fournol" population which utilized the Gravettian culture, well-known for their portable Venus figurines. Through the Last Glacial Maximum between 19-17 thousand years ago, a new ancestry emerged in southeast Europe which shared ancestry with the older Bacho Kiro peoples: the "Villabruna cluster". These peoples then met and admixed with descendants of the Gravettians which survived the intense cold by retreated southward to the Mediterranean. Eventually, by the end of the glacial period around 11 thousand years ago, the hunter-gatherer population of Europe had effectively homogenized through constant admixture both within and without. There was a Western Hunter Gatherer or "Oberkassel" ancestry that can be distinguished from an Eastern Hunter Gatherer or "Sidelkino" ancestry which originated from the Ancent North Eurasians (Posth, et al. 2023).
Spread of Ancient North Eurasian ancestry (naturalearthdata.com CC BY-SA 4.0)
The Ancient North Eurasians diverged from the Early Europeans around 39 thousand years ago, and are well-represented in the archaeological record by the peoples of the Mal'ta–Buret' culture, who inhabited the lands west of Lake Baikal in Siberia around 24 thousand years ago (Reich, 2018). Clearly, the nomadic movements of the Ancient North Eurasians were widespread and successful. Though as a population they no longer exist - surviving as late as 4,000 years ago in the Tarim Basin (Zhang, et al. 2021) - they seem to have frequently interbred with almost every group they met and thus contributed significant ancestry to Native Americans, Paleosiberians, Ugaric-speaking peoples, and the descendants of the Indo-European-speaking Yamnaya culture as far apart as Spain and India. Yet another example of the common threads uniting seemingly disparate groups.
Farmers and Riders in the West
Levels of admixture in Middle Eastern and North African peoples (from Serradell, et al. 2024)
As mentioned previously, genetic studies have been few and far between in North Africa as well as Southwest Asia (the Middle East), but recent work has began to fill in some gaps in our knowledge.
A 2024 paper using modern genomes has discovered a series of "soft-splits" or non-rigid genetic divergences for the ancestral populations of the Amazigh and Arab peoples (Serradell, et al. 2024). In essence, both groups belong to the Western Eurasian group and are close relatives of living Europeans but throughout their histories have incorporated extensive geneflow from both Africa and Europe over the last 18 thousand years or so. The Amazigh peoples were the first to diverge and constitute a return to the African continent where they today remain across much of North Africa; incidentally, it is generally understood that the Amazigh have some relation towards the ancestry of the Guanches of the Canary Islands (Serrano, et al. 2023). The Arabs, in contrast, share a closer relationship with European peoples and diverged around 8.6 thousand years ago. The Islamic expansions of the early Postclassical Period would, in turn, spread Arabic ancestry across Africa and Eurasia.
AncientDNA from the late glacial and postglacial periods seem to add further evidence that Southwest Asia was a hub of genetic diversity, with evidence of several groups living in relative isolation prior to the origins of agriculture around 11 thousand years ago (Reich, 2018). In particular, populations living in Anatolia (modern-day Türkiye), the Zagros Mountains of Iran, and the Levant (e.g. Palestine & Syria) share differing levels of ancestry between each other. Ancient Anatolians show evidence of admixture with Early European Hunter Gatherers, while early peoples of the Zagros show more admixture with Caucasus Hunter Gatherers (Chataigner, et al. 2024), and Levantine peoples show high levels of shared ancestry with East and North Africans.
As agricultural practices began to take root, these groups began to come into contact with each other so that, for example, farmers in Iran constituted ancestry from both Anatolian and Iranian foragers (Shinde, et al. 2019). As well, farmers began to spread to new lands in such numbers that they would significantly change the genetic landscapes wherever they went. Anatolian farmers began to spread into Europe around 9,000 to 8,500 thousand years ago, and over a period of just 3,000 years they had near-fully spread across Europe. These people, now known as "Early European Farmers", would not only end the lifeways of the older foraging groups but effectively admix them out of existence through a genetic sweep (Tsoupas, et al. 2025). According to geneticist David Reich: "Today, Early European Farmer ancestry remains widespread throughout Europe, ranging from about 60% near the Mediterranean Sea (with a peak of 65% in the island of Sardinia) and diminishing northwards to about 10% in northern Scandinavia. According to more recent studies the highest Early European Farmer ancestry found in modern Europeans ranges from 67% to over 80% in modern Sardinians, Italians, Greeks and Iberians, with the lowest ancestry found in modern Europeans ranging from 35% to 40% in modern Finns, Lithuanians and Latvians" (Reich, 2018).
One model for the spread of the Western Steppe Herders (Koba-chan, CC BY-SA 3.0)
Then, as if that weren't enough, another genetic sweep would overtake Europe. Around 5,300 years ago, the Yamnaya culture emerged on the Pontic–Caspian steppe from a combination of Caucasus, Eastern European forager, Ancient North Eurasian, and Southwest Asian farmer admixture (Lazaridis, et al. 2022). They are genetically and archaeologically well-documented as kurgan (burial-mound)-building bronze age horse-back riders and they are widely viewed as the originators of the Indo-European language family (Reich, 2018). Around 4,900 years ago, these "Western Steppe Herders" began to expand across Eurasia, moving westward into Europe, eastward into Siberia, and southward into present-day Pakistan and India. Genetic evidence suggests that, at least for Europe, the sweep commenced over a thousand-year period (Allentoft, et al. 2024), and that it involved a complex process which effectively subsumed most of the populations Early European Farmers in all but a few regions: a widely-studied example are the Basques, who have maintained genetic isolation since the European Iron Age and speak a non-Indo-European language (Flores-Bello, et al. 2021).
Similar stories played out across Africa and Eurasia. Levantine agriculturalists contributed genetic ancestry to Northern and Eastern African groups over 3,000 years ago, some of which was picked up by Khoesan pastoralists who migrated with their herds into Southern Africa (Liu, et al. 2021). One farming population distantly related to ancient Iranians spread into South Asia and contributed substantial ancestry to the founders of the Indus Valley cities (Shinde, et al. 2019). Likewise with Europe, present-day India and Pakistan experienced several genetic incursions over millennia (Narasimhan, et al. 2019; Reich, 2018). It's earliest Eastern Eurasian ancestry will be illuminated more in the next section, but it is worth mentioning that prior to 9,000 years ago the subcontinent was primarily inhabited by hunter-gatherer groups known to ancientDNA researchers as "Ancient Ancestral South Indians". When the Iranian-related farmers arrived they quickly spread agriculture throughout the region, and some researchers suspect that the Dravidian-speaking peoples derive much of their ancestry from admixture with the Indigenous groups there (Bellwood, 2022): genetically, they are known as "Ancestral South Indians". The Iranian-related farmers also spread northward into the Hindu Kush, where they eventually came into contact with the expanding Western Steppe Herders: these, in turn, are known as "Ancestral North Indians". From there, between 4,000 and 3,000 years ago, these two ancestral groups converged, with the Ancestral North Indians contributing anywhere from 39–71% ancestry in living South Asian groups today (Reich, et al. 2009).
East Eurasia
Simplified overview of the earliest diverging populations in Eurasia (from Yang, 2022)
Let's back-track a bit to the OoA movements around 45 thousand years ago. Parallel with the western Eurasian expansion, there was an eastern Eurasian movement of Initial Upper Paleolithic peoples as well. Unlike the former, the peoples of the east were not swept over genetically by a second wave but instead diversified into at least three lineages: the aforementioned Ancient Ancestral South Indians, the Australasians, and the Ancient East and Southeast Asians (Yang, 2022).
As in Southwest Asia and Europe, where Homo sapiens encountered and admixed with Neanderthals, so too did Homo sapiens in Eastern Eurasia encounter Denisovans. In contrast, however, there appears to be evidence of multiple admixture events at different times and with several highly-divergent Denisovan populations (Ongaro & Huerta-Sanchez, 2024). One event likely occurred in Southeast Asia with the ancestors of Aboriginal Australians, Negritos (a term for often small-statured Indigenous peoples in Island Southeast Asia), and the peoples of New Guinea and the Melanesian Islands, where today all these groups possess around 5% Denisovan DNA in their genome. Other events occurred on the mainland with the ancestors of South Asians, East Asians, and Native Americas, who possess 0.2% Denisovan DNA in their genomes. The contrast between the two can be explained by successive genetic sweeps with new Homo sapiens groups which have smothered the Denisovan signal.
The genetic signal for the Ancient Ancestral South Indians is very small and has only been recovered from a few individuals throughout South Asia who lived between 5,000 and 1,500 years ago (Yang, 2022). Nevertheless, they appear to have had a widespread presence on the subcontinent prior to the arrival of agriculturalists. Genetic comparisons with some isolated ethnic groups have been made, showing that the Adivasi of Sri Lanka share over half their genomes with AASI ancestry (Aragon, et al. 2025), while the Andamanese Islanders - once thought to represent members of this group - are now known to be only distant relations (Yang, 2022).
The Australasian group will be discussed in the next section, but by far the group with the largest and most complex population history are the Ancient East and Southeast Asians, who prior to 40 thousand years ago were widespread across the mainland and represented two genetic lineages.
Across Southeast Asia - which, during glacial periods, was not a series of islands but an extension of the mainland - was the "Hòabìnhian" group. These peoples utilized flaked cobble tools and inhabited regions as far apart at Yunnan, China and Laos; as well they share a common ancestry with the Andamanese Islanders. Further north along a band stretchin from South Asia to mainland Southeast Asia was a "Yunnan" group which represented the primary ancestral population of the Austroasiatic-speaking peoples like the Vietnamese and Khmer (Tagore, et al. 2021). Still further north was the "Tianyuan" group, well represented by individuals recovered from northern China 40-33 thousand years ago (specifically AR33K and Tianyuan). These groups formed the majority of Eastern Eurasian genetic diversity, alongside the eastern-most Ancient North Eurasian populations known to geneticists as "Ancient Northern Siberians" and represented by the 31 thousand-year-old individuals from the Yana River in Russia.
Even before the end of the Last Glacial Maximum, these different ancestries were admixing and diversifying. An individual found at Salkhit, Mongolia was found to share ancestry with both the Tianyuan group and Ancient Northern Siberians (Mao, et al. 2021). From 39 thousand years ago, the Tianyuan group began to diverge into a number of different populations, with one group crossing into the Japanese archipelago by at least 25 thousand years ago to become the ancestors of the Jōmon people, and another more mysterious group entering the Tibetan Plateau by 21 thousand years ago (Zhao, et al. 2009). From there, the genetic trail shows a large-split between "Northern East Asians" and "Southern East Asians" between 28 and 22 thousand years ago (Mao, et al. 2021). These source populations would effectively contribute the majority of subsequent ancestry to living East and Southeast Asian peoples, and eventually subsume many of the older groups through genetic sweeps much as had occurred in Europe.
A key admixture event occurred around 25 to 20 thousand years ago between some Ancient Northern Siberians and a group of Northern East Asians which gave rise to the "Ancient Paleosiberians", who are represented by two individuals: Kolyma1 and Ust-Kyakhta-3, who lived between 14 and 9,000 years ago. This group would give rise to both "Modern Paleosiberians" and the Amerindians or Native Americans (Yang, 2022). I'll consider the history of Indigenous Americans in a later section, but the Modern Paleosiberians will be of interest here. Over time, this group spread over a wide-range of northern Eurasia, contributing ancestry to the Chukotko-Kamchatkan-speaking peoples of far-eastern Siberia (e.g. the Chukchi and the Koryak), the Nivkh or Gilyak peoples of Sakhalin Island and mainland Russia, the Yeniseian-speaking peoples of central Siberia, and even the Uralic-speaking peoples, who spread far westward from Yakutia into northeast Europe around 4,500 years ago, today represented by the Finns, Hungarians, Estonians, and Sámi (Zeng, et al. 2025). Much of the earlier European hunter-gatherer ancestry in Finno-Scandinavia would be subsumed by this last group. Likewise in Siberia, the Paleosiberians would effectively replace the earlier Ancient Northern Siberian peoples (Sikora, et al. 2019).
Farmers and Riders in the East
Eastern Eurasia over the last 15,000 years (from Yang, 2022)
There is a very complex history of genetic exchange and migrations following the end of the last Ice Age. Both the Northern and Southern East Asians experienced continued diversification as their populations swept over the region.
By 14 thousand years ago, one group of Northern East Asians emerged in the Amur region between present-day Russia and China, and was found to have contributed to the genomes of the Ancient Paleosiberians as well. This Amur group (sometimes referred to as "Neosiberians") interacted widely with other populations in Mongolia and the Central Asian steppes from 10 thousand years ago, and underwent a large-scale population expansion which settled across much of Siberia and eventually overtook the Paleosiberian peoples from much of their lands (Wong, et al. 2017; Sikora, et al. 2019). It is widely believed that this genetic expansion was accompanied by the spread of the Altaic or Transeurasian language family, including speakers of the Tungusic (e.g. the Evenks and Manchus), Mongolic, and Turkic languages. Interactions with Indo-European-speaking groups would facilitate the introduction of horses and allow for further migrations such as those documented in recorded history.
In the Yellow River region of China, another group of Northern East Asians with close affinities to the Amur group was settling down into village communities. By 10 thousand years ago they had developed millet-based agriculture and were likely speaking a proto-form of Sino-Tibetan. As farmers have often done, they interacted widely with neighboring peoples and expanded their populations far and wide. There is evidence that one group migrated westward into the Tibetan Plateau around 5,800 years ago, acquiring an adaptive gene towards life in high mountains which had been distantly inherited from Denisovans (Xiong, et al. 2025). We know from the archaeological record that farming also originated along the Yangtze River region, south of the Yellow River, where the people there developed rice-based agriculture: until recently ancientDNA from this region was unknown. A recent 2025 paper found that these peoples represented a distinct but closely-related group to the Yellow River populations, hinting at past admixture events (Xiong, et al. 2025). The Han Chinese, today the largest ethnic group in the region, descend from admixture between groups along the lower Yellow River and the northern Yangtze River (Reich, 2018).
It has been argued that the Korean and Japanese languages also belong to the Transeurasian family, but the ancestries of these peoples seem to be as complex as others in East Asia. The modern Japanese, for example, have been shown to constitute a tripartate ancestry from the Indigenous Jōmon people, a mysterious Northern East Asian "West Liao" people which adopted agriculture and entered the archipelago from the Korean Peninsula, and a later agriculturalist influx related to the Yellow River group (Cooke, et al. 2021). Modern Koreans show close affinity to both the West Liao people and the Amur group (Sun, et al. 2023).
Some of the ancestry of the Yangtze River farmers could be traced to the Southern East Asian populations, which until now have remained undiscussed. Between 8,000 and 6,000 years ago, a number of groups had emerged from this ancestral population, including the "Guangxi/Longlin" group in southern China which is not detected in any of the living peoples in that region today (represented by the "Red Deer Cave People"), and the "Fujian" group which seems to have also lived ancestrally in southern China but played a far more long-lasting role in world history.
The spread of rice farmers into Southeast Asia (Obsidian Soul, Public Domain)
The peopling of Southeast Asia involved a multitude of southward population expansions involving hunter-gatherers and agriculturalists. The first movements involved groups related to the ancestors of Indigenous peoples in Australia and Melanesia, these being the aformentioned Hòabìnhian peoples. Some ethnic groups today, like the Punan of Borneo, show evidence of genetic continuity with these first groups (Kusuma, et al. 2023), while others like the Negritos of Malaysia show connections to the Hòabìnhian as well as Northern East Asian farmers (Aghakhanian, et al. 2022). The peoples of the Philippines consist of ancestry from at least four main movements of people into the islands, some within the last 15 thousand years (Larena, et al. 2021).
In fact, it seems that within the last 5,000 years or so, there was a large influx of agriculturalists which seems to have largely overtaken much of the original hunter gatherer populations in Southeast Asia, isolating many of them - in the case of, say, the Negritos - or fragmenting their communities - in the case of the Austroasiatic-speaking peoples (Yang, 2022; Ma, et al. 2024). The majority of this ancestry seems to descend primarily from the admixed Yellow/Yangtze farmers and the Fijian group (thus, constituting both Northern and Southern East Asian ancestries). Linguistically, these movements have been linked with the origin and spread of the Kra-Dai (e.g. Tai and Lao-speakers), Hmong-Mien, and Austronesian language families (Yang, et al. 2020).
Australia and the Pacific Islands
The peopling of Australia and Melanesia, with representative archaeological sites and hypothetical movements (from Tobler, et al. 2017)
A period of time between 49 and 45 thousand years marks the presence of Homo sapiens on the continent of Sahul, a landmass consisting of Australia, Tasmania, and New Guinea which periodically emerged during periods of low-sea levels during the last Ice Age. There are a number of earlier sites known - some going back as far as 65 thousand years - but it is unclear how accurate some of these dates are or whether they represent genetically unsampled groups which did not contribute to living Indigenous populations.
Evidence from the DNA of Aboriginal Australians confirms a continuous presence on the continent since the first settlement, following a single rapid migration from Southeast Asia that quickly reached all parts of the landmass (Tobler, et al. 2017). Even while Sahul was in existence, geneflow between Australian and New Guinean groups seems to have ceased between 40 and 25 thousand years ago - corresponding to the formation of the now-extinct Super-Lake Carpentaria - and from that time the two regions experienced marked lineage diversification (Malaspinas, et al. 2016). One group, associated with the Pama–Nyungan language family, appears to have emerged and spread across much of Australia within the last 10 thousand years or so.
In New Guinea, populations maintained genetic continuity as well, while also expanding into neighboring islands. The Bismark and Solomon Islands were settled between 43 and 39 thousand years ago, while one westward expansion settled on the island of Sulawesi and admixed with a Hòabìnhian-related group, becoming the ancestors of the Toalean peoples (Carlhoff, et al. 2021).
Movements of South Pacific wayfinders (from Ioannidis, et al. 2021)
Much more recent in time was the settlement of the remaining Pacific islands. Genetic studies have, by now, seemingly cemented an understanding that the very distant origins of the Polynesians lie in Taiwan and mainland China. Austronesian-speaking peoples inhabited southeastern coastal China and Taiwan between 6,000 and 5,000 years ago, consisting of genetic ancestry from Yangtze River farmers and Taiwanese hunter gatherers (Xiong, et al. 2025). Between 5,000 and 4,000 years ago, this population began a continuous southern expansion through the Philippines, Malaysia, and Indonesia. Some of the groups settled there and show evidence of admixture with Negritos and Austroasiatic-speaking peoples (Lipson, et al. 2014), while others sailed through the Indian Ocean and settled on Madagascar and the East African coast.
One group seems to have largely bypassed New Guinea (by then having flourishing agricultural communities in the highlands) and settled on the Bismark and Solomon Islands around 3,600 years ago. From there, the archaeological record tells us, emerged the Lapita Culture, which pioneered the design for a double-hulled outrigger canoe which could traverse more open waters (Bellwood, 2022). Just 100 years later, groups had managed to travel north to the Mariana Islands, (Pugach, et al. 2020). Between 3,200 and 2,200 years ago other members of the Lapita traveled further east, reaching as far as Fiji, Tonga, and Samoa, after which further voyages ceased for over 1,500 years: it was during this period that a recognizable Polynesian population formed. There is genetic evidence of distant contact with the peoples of New Guinea, and it appears that some individuals from that region traveled to the South Pacific on later voyages (Reich, 2018).
Beginning in the 800s AD - as the European Middle Ages were underway - there was a second great pulse of Polynesian expansion across the rest of the Pacific islands (Ioannidis, et al. 2021). The Southern Cook Islands, the Australis, the Society Islands, the Tuamotu Archipelago, and the Marquesas were all settled over a period of a few hundred years. The distant island chains of Hawaiʻi, Rapa Nui (Easter Island), and Aotearoa (New Zealand) were all settled by the 1250s. In all this time, the ingenuity of the wayfinders ensured continuious contact between several island groups, as evidenced, for example, by the Tuʻi Tonga Empire whose influence spread as far as the Tuvaluan Archipelago by the 1500s (a distance of over 1,300 kilometers). There is even evidence of contact with South America: around 1200, a group of Polynesian wayfinders reached a region roughly in present-day Colombia, admixed somehow with the Amerindians there, and transferred this ancestry to the South Pacific, long before the rest of the far eastern islands had been discovered (Ioannidis, et al. 2020).
The Americas
The first peopling of the Americas (from Willerslev & Meltzer, 2021)
As mentioned earlier, the Indigenous peoples of the Americas can ultimately trace their ancestry to an admixture event between 25 and 20 thousand years ago between Ancient Northern Siberians and a group of Northern East Asians (Yang, 2022). The region of Beringia was dry cold land around this time and seems to have supported a small but genetically-rich group of people by 18 thousand years ago, which had begun to rapidly diverge into a number of lineages which became the founding populations of the Amerindians (Moreno-Mayar, et al. 2018). One of these, termed the "Ancient Beringians" (represented by two 11,500-year-old children from Alaska), seem to have around until at least 9,000 years ago but may have been genetically subsumed by other peoples. Three other groups, currently mysterious but present in the genomes of some Central and South American Indigenous groups, seem to have also diverged around this time: "Unsampled Population A" was detected in a few living Mixe peoples, "Unsampled Population A2" was detected in northern and central Mexico (Villa-Islas, et al. 2023), while "Population Y" has been found across Amazonia and the Andes in individuals up to 10 thousand years old, but curiously retains genetic signals from both the ancient Tianyuan group and the ancestors of Australasian peoples (Ferraz, et al. 2023). There has been much controversy about Population Y, with some researchers speculating an alternative model that this group represents an earlier entry into the Americas (Raff, 2022). Further research has revealed more deeply-divergent lineages: a 5,600-year-old individual from Big Bar Lake, British Columbia and sampled DNA from historic & living members of the Blackfoot Confederacy date to this period of rapid divergence (First Rider, et al. 2024).
At present, all other Amerindian peoples sampled descend from two sister-lineages that emerged on the North American continent between 17,500 and 14,600 years ago (Moreno-Mayar, et al. 2018). One, dubbed the "Northern Native Americans" were the primary source of ancestry to the Algonquian, Salishan, Tsimshian, and Na-Dené-speaking peoples, while the "Southern Native Americans" are represented across both American continents, including in individuals associated with the widespread Paleolithic Clovis culture (Raff, 2022).
The spread of peoples across the Americas during the end of the last Ice Age proceeded with a rapidity matched by earlier times and places. Tierra del Fuego, the southern tip of South America, was settled twice by 14 thousand years ago by groups who became adapted to marine and terrestrial resources (Balentine, et al. 2022). There is even evidence of not only north-to-south migrations but south-to-north migrations as well, with genetic evidence of an Atlantic coastal expansion which settled in northeastern Brazil (Dos Santos, et al. 2022).
Movements of peoples within the Americas over the last 11,000 years (from Willerslev & Meltzer, 2021)
Some groups in the Americas retained a long-standing regional continuity in their homelands: a recent study found that the people of central Mexico - the region of Teotihuacan and the Aztec Triple Alliance - share the same genetic ancestry from pre-Hispanic to modern times with no evidence of outside genetic infusion (Villa-Islas, et al. 2023). Other groups show evidence of admixture and further population expansions: Members of the "Unsampled Population A" group expanded from Central America through much of South America from 9,000 years ago, subsuming the earlier Clovis-related genetic signatures (Raff, 2022). DNA from peoples of the California Channel Islands has been found in Andean individuals, pointing to an admixture event after 5,000 years ago (Posth, et al. 2018). The genetic blueprint of the Maya region seems to have been influenced by the movement of a group related to the Chibchan-speaking peoples of southern Central America and present-day Colombia after 5,600 years ago (Kennett, et al. 2022). In the Andes, the site of Machu Picchu has revealed that the Inka Empire consisted of a retainer community of peoples from as far as Amazonia (Salazar, et al. 2023). The peopling of the Caribbean likewise proceeded in multiple waves, with earlier hunter gatherer groups who arrived 5,000 years ago eventually being subsumed by agriculturalists - the ancestral Taíno - from northern Amazonia over the last 2,800 years (Raff, 2022).
Even after Beringia was swallowed up by rising sea-levels, the region remained a hot-spot of human diversity and expansion. There is evidence of geneflow from Modern Paleosiberian groups into North America from 11,500 years ago (Moreno-Mayar, et al. 2018), and vice-versa there was consistent Native American geneflow into northeast Asia over the last 5,000 years which contributed "non-negligible amounts" of ancestry into the ancestors of the Koryak, Chuckhi, and Itelmen peoples (Wang, et al. 2023). The peopling of the North American Arctic proceeded in a step-wise manner: around 5,500 years ago there was movement of "Paleo-Inuit" peoples from Kamchatka that made it as far as Greenland by 4,400 years ago; later on, the people of the Thule culture or "Neo-Inuit" emerged in Alaska between 4,900 and 2,700 years ago, through an admixture event with Modern Paleosiberians. This group began to spread over the Arctic from around the 1200s AD and reached Greenland after a thousand years, in that time sweeping over the genetic signal of the earlier Paleo-Inuit peoples: the living Inuit, Yup'ik, and Unangax̂ (Aleut) peoples are primarily descended from the Neo-Inuit expansion, while the DNA of the Paleo-Inuit survives in admixed form with both Unangax̂ & Na-Dené-speakers in North America and modern Paleosiberians (Raff, 2022).
So far from being an isolated landmass, the Americas remained connected in important ways to the northeast of Eurasia as well as the Pacific islands.
Wrapping-Up
If you made it this far, I offer my sincerest thanks.
As you can probably guess, the story of human migrations did not end in prehistory. It still continued well throughout the Postclassical World and on to the modern age of colonialism and the industrial revolution. It involved the creation of new ethnic groups - Latin Americans being a prime example - while also spreading different populations far and wide over the planet through every means. In the 21st Century, Homo sapiens has continued to be a monotypic, geographically-diverse but near genetically-identical species. Despite all these past popultion expansions stretching back hundreds of thousands of years, the data still stares us in the face: on average, humans are more genetically similar within populations than between populations, with the DNA underpinning supposed "racial characteristics" being miniscule proportionally and non-correlated with each other. Race is not a scientifically accurate way to understand human biological diversity.
I hope these three articles have proviced some insights into how human diversity is understood today, and changes the way you think about "biological race". Humans have a rich and varied past of continuity, population expansions, and admixture that is better understood on its own terms, rather than that be pigeon-holed into a few discrete racial roups. Doing so brings the science of biological anthropology in line with how biologists study the rest of life on Earth, and that benefits everyone.
Book References
Peter Bellwood. The Five Million Year Odyssey (Princeton University Press, 2022)
Jennifer Raff. Origin: A Genetic History of the Americas (Twelve, Grand Central Publishing, 2022)
David Reich. Who We Are and How We Got Here (Oxford University Press, 2018)
Paper & Article Citations
Farhang Aghakhanian, et al. 2022. Sequence analyses of Malaysian Indigenous communities reveal historical admixture between Hoabinhian hunter-gatherers and Neolithic farmers (Scientific Reports)
Morten E. Allentoft, et al. 2024. Population genomics of post-glacial western Eurasia (Nature)
Jose A. Urban Aragon, et al. 2025. Population histories of the Indigenous Adivasi and Sinhalese from Sri Lanka using whole genomes (Current Biology)
Elena Arciero, et al. 2025. Whole-genome sequences provide insights into the formation and adaptation of human populations in the Himalayas (Current Biology)
Christina M. Balentine, et al. 2022. Evaluating population histories in Patagonia and Tierra del Fuego, Chile, using ancient mitochondrial and Y-chromosomal DNA (American Journal of Biological Anthropology)
Adrian Viliami Bell, 2023. Selection and adaptation in human migration (Evolutionary Anthropology)
Inga Bergmann, et al. 2022. The relevance of late MSA mandibles on the emergence of modern morphology in Northern Africa (Nature Scientific Reports)
Anders Bergström, et al. 2021. Origins of modern human ancestry (Nature)
Selina Carlhoff, et al. 2021. Genome of a middle Holocene hunter-gatherer from Wallacea (Nature)
Christine Chataigner, 2024. The South Caucasus from the Upper Palaeolithic to the Neolithic: Intersection of the genetic and archaeological data (Quaternary Science Reviews)
Niall P. Cooke, et al. 2021. Ancient genomics reveals tripartite origins of Japanese populations (Science Advances)
Trevor Cousins, et al. 2025. A structured coalescent model reveals deep ancestral structure shared by all modern humans (Nature Genetics)
Andre Luiz Campelo Dos Santos, et al. 2022. Genomic evidence for ancient human migration routes along South America's Atlantic coast (Proc Biol Sci)
Shaohua Fan, et al. 2023. Whole-genome sequencing reveals a complex African population demographic history and signatures of local adaptation (CellPress)
Xiaobo Feng, et al. 2025. The phylogenetic position of the Yunxian cranium elucidates the origin of Homo longi and the Denisovans (Science)
Tiago Ferraz, et al. 2023. Genomic history of coastal societies from eastern South America (Nature Ecology and Evolution)
Dorothy First Rider, et al. 2024. Genomic analyses correspond with deep persistence of peoples of Blackfoot Confederacy from glacial times (ScienceAdvances)
André Flores-Bello, et al. 2021. Genetic origins, singularity, and heterogeneity of Basques (Cell Press)
Cesar A Fortes-Lima, et al. 2023. The genetic legacy of the expansion of Bantu-speaking peoples in Africa (Nature Portfolio)
Haechan Gill, et al. 2024. Reconstructing the Genetic Relationship between Ancient and Present-Day Siberian Populations (Genome Biology and Evolution)
Mateja Hajdinjak, et al. 2021. Initial Upper Palaeolithic humans in Europe had recent Neanderthal ancestry (Nature Portfolio)
Leonardo N. M. Iasi, et al. 2024. Neanderthal ancestry through time: Insights from genomes of ancient and present-day humans (Science)
Alexander G. Ioannidis, et al. 2021. Paths and timings of the peopling of Polynesia inferred from genomic networks (Nature)
Alexander G. Ioannidis, et al. 2020. Native American gene flow into Polynesia predating Easter Island settlement (Nature)
Douglas J. Kennett, et al. 2022. South-to-north migration preceded the advent of intensive farming in the Maya region (Nature Communications)
Pradiptajati Kusuma, et al. 2023. Deep ancestry of Bornean hunter-gatherers supports long-term local ancestry dynamics (Cell Rep)
Maximilian Larena, et al. 2021. Multiple migrations to the Philippines during the last 50,000 years (PNAS)
Iosif Lazaridis, et al. 2022. The genetic history of the Southern Arc: A bridge between West Asia and Europe (Science)
Mark Lipson, et al. 2020. Ancient West African foragers in the context of African population history (Nature)
Mark Lipson, et al. 2014. Reconstructing Austronesian population history in Island Southeast Asia (Nature Communications)
Yichen Liu, et al. 2021. Insights into human history from the first decade of ancient human genomics (Science)
M. Gallego Llorente, et al. 2015. Ancient Ethiopian genome reveals extensive Eurasian admixture in Eastern Africa (Science)
Marieke van de Loosdrecht, et al. 2018. Pleistocene North African genomes link Near Eastern and sub-Saharan African human populations (Science)
Minmin Ma, et al. 2024. Forager-farmer transition at the crossroads of East and Southeast Asia 4900 years ago (Science Bulletin)
Anna-Sapfo Malaspinas, et al. 2016. A genomic history of Aboriginal Australia (Nature)
Xiaowei Mao, et al. 2021. The deep population history of northern East Asia from the Late Pleistocene to the Holocene (CellPress)
Mayukh Mondal, et al. 2025. Resolving out of Africa event for Papua New Guinean population using neural network (Nature Communications)
J. Víctor Moreno-Mayar, et al. 2018. Terminal Pleistocene Alaskan genome reveals first founding population of Native Americans (Nature)
Aurélien Mounier & Marta Mirazón Lahr, 2019. Deciphering African late middle Pleistocene hominin diversity and the origin of our species (Nature Communications)
Vagheesh M. Narasimhan, et al. 2019. The formation of human populations in South and Central Asia (Science)
Linda Ongaro & Emilia Huerta-Sanchez, 2024. A history of multiple Denisovan introgression events in modern humans (Nature Genetics)
Cosimo Posth, et al. 2023. Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers (Nature)
Cosimo Posth, et al. 2018. Reconstructing the Deep Population History of Central and South America (CellPress)
Irina Pugach, et al. 2020. Ancient DNA from Guam and the peopling of the Pacific (PNAS)
Aaron P. Ragsdale, et al. 2023. A weakly structured stem for human origins in Africa (Nature)
Carolin Röding, et al. 2022. Mugharet el'Aliya: Affinities of an enigmatic north African Aterian maxillary fragment (American Journal of Biological Anthropology)
Lucy Salazar, et al. 2023. Insights into the genetic histories and lifeways of Machu Picchu’s occupants (Science Advances)
Jose M. Serradell, et al. 2024. Modelling the demographic history of human North African genomes points to a recent soft split divergence between populations (Genome Biology)
Javier G. Serrano, et al. 2023. The genomic history of the indigenous people of the Canary Islands (Nature Communications)
Vasant Shinde, et al. 2019. An Ancient Harappan Genome Lacks Ancestry from Steppe Pastoralists or Iranian Farmers (CellPress)
Martin Sikora, et al. 2019. The population history of northeastern Siberia since the Pleistocene (Nature)
Arev P. Sümer, et al. 2024. Earliest modern human genomes constrain timing of Neanderthal admixture (Nature)
Na Sun, et al. 2023. The genetic structure and admixture of Manchus and Koreans in northeast China (Annals of Human Biology)
Debashree Tagore, et al. 2021. Insights into the demographic history of Asia from common ancestry and admixture in the genomic landscape of present-day Austroasiatic speakers (BMC Biol)
Ray Tobler, et al. 2023. The role of genetic selection and climatic factors in the dispersal of anatomically modern humans out of Africa (PNAS)
Ray Tobler, et al. 2017. Aboriginal mitogenomes reveal 50,000 years of regionalism in Australia (Nature)
Alexandros Tsoupas, et al. 2025. Local increases in admixture with hunter-gatherers followed the initial expansion of Neolithic farmers across continental Europe (ScienceAdvances)
Leonardo Vallini, et al. 2024. The Persian plateau served as hub for Homo sapiens after the main out of Africa dispersal (Nature Communications)
Leonardo Vallini, et al. 2022. Genetics and Material Culture Support Repeated Expansions into Paleolithic Eurasia from a Population Hub Out of Africa (Genome Biol Evol)
Viridiana Villa-Islas, et al. 2023. Demographic history and genetic structure in pre-Hispanic Central Mexico (Science)
Ke Wang, et al. 2023. Middle Holocene Siberian genomes reveal highly connected gene pools throughout North Asia (Current Biology)
Eske Willerslev & David J. Meltzer, 2021. Peopling of the Americas as inferred from ancient genomics (Nature)
Jianxue Xiong, et al. 2025. The genomic history of East Asian Middle Neolithic millet- and rice-agricultural populations (Cell Genomics)
Melinda A. Yang, 2022. A genetic history of migration, diversification, and admixture in Asia (Human Population Genetics and Genomics)
Melinda A. Yang, et al. 2020. Ancient DNA indicates human population shifts and admixture in northern and southern China (Science)
Tian Chen Zeng, et al. 2025. Ancient DNA reveals the prehistory of the Uralic and Yeniseian peoples (Nature)
Fan Zhang, et al. 2021. The genomic origins of the Bronze Age Tarim Basin mummies (Nature)
Mian Zhao, et al. 2009. Mitochondrial genome evidence reveals successful Late Paleolithic settlement on the Tibetan Plateau (PNAS)
